Corsair HX650w 650W ATX PSU

Cables, Connectors & Internal Organs

Around the front of the unit we have the modular cable connector area which consists of five propitiatory flat style connectors and two 6-Pin PCI-E connectors. As you will have probably guessed, the flat style connectors are used for the SATA and Molex modular cables, whereas the PCI-E style connectors are used for....the PCI-E graphics card cables. This is exactly the same layout as the HX620W (but different to the HX750W/HX850W), and most likely indicates that Corsair decided to use the same OEM for the HX650w as they did for the HX620w (Seasonic), rather than finishing off their new HX range with just CWT built units.

In addition to the modular connectors, two essential cables - the EPS-12v and ATX are hard wired into the unit. This not only ensures that critical system components get a good; clean supply of power direct from the PSU, but also avoids potential situations where an ill-fitted modular cable could cause system instability or even kill components.

Corsair HX850W Connectors

ATX Connector

Native

1x 20+4 Pin

EPS-12v / P4-12v Connector(s)

Native

1x 4+4 Pin

Molex Connectors

Modular

8x

Floppy Disk Connectors

Modular

2x

SATA Connectors

Modular

9x

PCI-E Connectors

Modular

2x 6+2 Pin

A total of 7 modular cables has been included by Corsair, meaning that every cable can be plugged into the unit at the same time. Although it's sometimes nice to have a few spares of each modular cable type, It's highly unlikely that the average user buying a 650W PSU will be using more than eight molex or nine SATA connectors in their system.

While on the subject of modular cables, its good to see that Corsair have stuck with the black ribbon style wires rather than going down the sleeving route. Personally I love the look of these cables as they are easily camoflaged inside a case with black internals and look so much more professional than wires wearing a pear of stockings! Of course, the only downside to them is that they only bend easily in two directions (much like a PATA cable) meaning that they are slightly less flexible than normal bunched cables which can bend in any direction.

Going in for a closer look at the ATX 24-Pin, EPS 8-Pin and PCI-E 8-Pin connectors we can see that Corsair have retained compatibility with older/lower range motherboards and graphics cards by allowing certain parts of the connectors to be snapped off in order to support 20-Pin, 4-Pin and 6-Pin standards respectively. This feature has been dropped from a lot of manufacturers PSU's, so it's good to see that Corsair realise the importance of keeping this feature on the lower wattage models.

The Guts

With the HX620W literally rocketing Corsair's PSU venture into success, its understandable that they wouldn't want to make too many changes to the HX650W. This is certainly visible when you lift the lid off the HX650W, as the general layout at least, is pretty much a direct clone of its predecessor.

Everything inside the unit is well arranged with all cables on the output side tidily bunched together. A black PCB replaces the original green PCB of the HX620W maybe hinting that Corsair have got a little more specific with their requirements from Seasonic this time around. The main transformer for the +12v, +5v and +3.3v rails inside the unit is positioned right up against the modular backplane with a smaller transformer solely responsible for the 5vSB (stand-by voltage) rail over on the right.

Sitting slap bang in the middle of the unit is a tasty Japanese manufactured Nippon Chemicon capacitor that performs a large part of the input filtering for the primary side of the unit. The markings on the capacitor suggest that it is rated up to 400v at 105°C with a respectable 560 micro Farads (uF) capacitance. Over on the secondary (low voltage) side are a collection of various spec capacitors, once again all manufactured by Nippon Chemicon.

An EMI filtering circuit has been installed just behind the AC inlet on a rather tidy PCB. This should help to keep any internally generated noise from the MOSFET's and other components contained within the device, while also preventing any external AC line noise from entering the PSU. And finally a 7 blade 120mm brushless fan manufactured by ADDA keeps everything cool.

This fan carries a model number of AD1212HB-A71GL and is actually the very same fan used inside the HX620W. Lets check out the specs:

During a recent conversation with Corsair they tell me that the fan profile for the HX650w has been adjusted to be even quieter than the HX620W. This is probably owing to the (hopefully) higher efficiency of the HX650W with less energy being wasted as heat.

Is the 7 year warranty applicable to the modular (HX) series only, or does it cover the TX PSU's as well? local etailers have variously listed 5 and 7 year warranty's. Not a major as I'm sure either would last the distance. Awesome review.

All - Any thoughts on these items relative to replacing my stock PSU with one of these animals? Dell's notorious for arranging its grilles and mount points so as to only "allow" Dell replacement parts. I have an XPS Studio 435T/9000 (Core i7 920) and am worried about 3 things.

1) Form and fit (not afraid of a little metal work, however)

2) cable management (more along the lines of reach and airflow than aesthetics), and

These Dells are notorious for crashing when presented fake sine waves from their power sources. Any idea if the Corsairs care if it's a pure or fake sine wave? Ever test that? If interested pick up an APC BX1300G and see if your PSUs puke when it goes into battery mode... I'd be real interested in the result!

To be honest I have little (read:no) experience with aftermarket PSU's in Dell machines. The last I heard tho was that they switched around certain cables on the ATX connector so that only their PSU's would work and anything else would go *bang*. Not sure if this is still the case though?

All the recent Dell machines I have replaced PSUs in have had standard ATX (albeit crappy) units in them. I would think yours is no different, the only issue I can forsee is if there is enough room in the case for a new one, since Dell OEM PSUs tend to be on the short/small side and the Corsair units are a little bigger. Remember you'll need some cable clearance too. The only newer Dells that I've worked on with non-standard PSUs were smaller form factor machines, which is almost to be expected, though even some of the larger towers (probably not XPS) have been more narrow than normal.

Never seen a Dell with the ATX connectors switched round wrongly yet, I would hope that they'd also change the plug so that a standard one simply wouldn't fit in that case, who knows if they do or not.

I can see many complaints on the net about your PSU having problems like you mentioned, but no issues with Corsair units in the same way, so I would think a decent quality unit would solve the problem or not present the issues you are concerned about.

Remember, if you buy a unit from the internet, you can use the Distance Selling Regulations to get it returned if you find out it won't fit, but you do only have 7 days to do that and obviously you mustn't damage it.

Hope that helps.

I have a Corsair HX620 ready for RMA (still) and by the sounds of how they operate I may get back one of these newer units, glad to hear it's at least an improvement on the old one.

Thanks for the feedback and sharing your observations/experience. I've been inside the XPS tower - it seemed pretty roomy, bet then again I wasn't trying to replace the biggest blob inside the box at the time. Based on your and Jim's reply I guess the best thing to do is get a multimeter out and check everything before trying to slip it in place. Agree - not changing the plug while messing with polarities and voltages would be criminal. I'm building my next box...

Thanks again both. I'll report back after the Corsair arrives (tomorrow as scheduled).

It seems that starting after September of 1998 Dell defected from the cause of industry standardization and began using specially modified Intel supplied ATX motherboards with custom wired power connectors. Of course they also had custom power supplies made that duplicated the non-standard pinout of the motherboard power connectors.

An even bigger crime than simply using non-standard power connectors is that only the pinout is non-standard, the connectors look like and are keyed the same as is dictated by true ATX. There is nothing to prevent you from plugging the Dell non-standard power supply into a new industry standard ATX motherboard you installed in your Dell case as an upgrade, or even plugging a new upgraded industry standard ATX power supply into your existing Dell motherboard. But mixing either a new ATX board with the Dell supply or a new ATX supply with the existing Dell board is a recipe for silicon toast. How do you like your fried chips, medium or well done?

So - I ordered an HX750W from the net and after doing so thought it prudent to call Corsair to discuss this before installing. Explained my situation to the quite knowledgable tech; mainly the story on the factory PSU, speed bumps people had run into, and my problem with the OEM power supply not liking the "dirty" AC signal coming from my UPS's inverter. He said he'd never seen that problem with a Corsair, so that was the first bit of good news. I was torn between sticking with the old PSU and upgrading to a pure sine wave UPS (less risk) - or - buying a new PSU and sticking with my relatively inexpensive UPS (much less cost despite making a major upgrade to the PC itself). Whilst speaking with him he urged me to verify (with Dell) that my motherboard was ATX12V 2.2 (& backward) compliant, had a 20+4 pins main power plug and either an 8 pins or 4 pins power plug for the CPU. So off I went first to Intel to read the ATX 2.x spec. Found pinouts and other information useful to non-Dell users - since Dell only publishes scant marketing level descriptions (hardly full specs). So then off I went to (useless) Dell. The only thing they could tell me was their part number (F217J) for my original PSU - couldn't recommend any others as replacements. I cross-referenced that to a Flextronics Model #VP-0900073-000. Couldn't verify that it was ATX 2.2 compliant, but found a few posters out there who claimed to have successfully replaced this exact model with a number of differing brands, all ATX 2.2 compliant PSU's. The new Corsair arrived yesterday and down went the PC to the workshop. I cracked the machine open, cleaned and dusted, took a bunch of pictures and measured stuff. Decided it would fit and it was safe to open the new Corsair.

Wow - was I thrilled when I opened up that box! High quality nylon pouch for the modular cables, packaging like I've never seen before (velvet-like bag containing the PSU), wire ties, extra mounting screws and a very well written installation guide - even a metal "Powered by Corsair" logo tag for the outside of the machine. I was really impressed. So, the new PSU was about 1/2" shorter and about 7/8" longer, but turns out those dimensions don't matter much in my chassis. True to form, Dell's external mounting holes in the chassis didn't line up with the PSU. I extended the upper right chassis hole by making it a bit oblong (up and to the right about 1/8") and drilled a new lower left hole (about 5/16" directly below the original one). New PSU slipped right in and the holes lined up with their threaded mounting screw bosses in the PSU case. Because the Corsair isn't as tall, it didn't rest on a stamped-out horizonal chassis tang that the original rested upon, but there was no give or movement of any kind once the four screws were securely in place. The cables are some of the best quality I've ever seen. Took about 15 minutes to route stuff, another 10 minutes to tidy and close things up, and back up to the office I went.

Fired right up (I like my chips medium, thank you Jim). UPS monitoring S/W said I was burning 195W - about 50W less than before (I suppose that's a manifestation of the unit's efficiency... cool!). Then off to test the el cheapo APC Back-Up system (el cheapo - US$169 - not that cheap). Ran the self test and voila. It worked. This PSU's so quiet - what a purchase.

Jim and alexhull24 - I owe you a debt of gratitude. Thanks for the prudent warnings and good advice - and Jim - thanks for the exceptional review the 650. While I didn't necessarily write this for just you gents, I thought you might appreciate the detail and the news on the XPS Studio 435T's ATX 2.2 compliancy. Maybe somewhere along the line Dell got the message... Then again, probably just an "oversight" on their part.

One footnote. Someone out there blamed Active PFC as the root cause of my problem between the PSU and the UPS. Not true. The old PSU is a switching PSU. Says so right on the label. Glad I didn't rule out Active PFC. Had I followed that "advice" I probably would not have bought this and may have ended up with the same problem... There you go, Jim. See if you can show that Switching PSU's can't handle the Step Approximated or Pulse Width Modulated sine waves. Maybe that's the root cause... Maybe it's just a piece of junk Dell OEM PSU that's the problem.

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